Reset your cable modem by unplugging the power and then plugging it back in. I alway unplug the router too. I power on the cable modem and let it finish its boot process then I turn on my router and wait a minute or two and that usually does it. Normally the IP address that's assigned to the router is assigned based on the MAC address of the device. Right below where you have circled on your drawing you'll see the WAN MAC Address. Resetting the cable modem will release the IP address and then the next device that tries to get one, which in this case would be your router, should get a valid IP address.